In recent years, in addition to a laptop personal computer, a number of types of tablet type mobile electronic terminal equipment typified by a smartphone which has evolved from a mobile phone have been commercialized. Such tablet type mobile electronic terminals include one which uses an optical touch panel.
In the optical touch panel, a group of light emitting diodes (LEDs) for infrared light and a group of photodiodes for receiving infrared light from the group of LEDs for infrared light are disposed so as to encompass a panel for display. Scanning lines generated by infrared light are extensively laid on the panel. By blocking these infrared scanning lines using a finger, a stylus pen, or the like, which position on the panel for display is touched is specified.
However, tablet type mobile electronic terminals of recent years are dominated by terminals of a type in which an antenna for a wireless local area network (LAN), or the like, is incorporated into a chassis and a function for performing radio communication is provided. Therefore, in the case of a tablet type mobile electronic terminal employing the above-described optical touch panel method, a structure is employed in which an antenna portion for performing radio communication is provided outside the group of LEDs for infrared light and the group of photodiodes for receiving the infrared light mounted on a main substrate.
As an antenna, for example, a planar inverted F antenna (hereinafter, referred to as a PIFA type antenna) is used. For example, as disclosed in Patent Literature 1, a planar radiation element of the PIFA type antenna is provided in parallel with a panel face.